After the end of the Cold War, the number of scientific publications dealing with Russian Arctic seas increased dramatically. These include compilations of Soviet-era data sets, as well as new data collected by international expeditions since the early 1990s. Several large, multidisciplinary projects were organized through Russian-German research partnership focusing on the Laptev and Kara seas. Notably, the Siberian River Run-off (SIRRO) project was aimed at investigating the effects of the discharge of western Siberian rivers on the Kara Sea. The importance of this topic is justified by the critical role of runoff in the formation and maintenance of the Arctic Ocean ice cover, and in controlling the deep-sea thermohaline convection in the Nordic seas. The Kara Sea receives more than one-third of the total runoff into the Arctic Ocean, predominantly from the Ob and Yenisey rivers, which drain a huge catchment area extending to the slopes of the Tibetan Plateau.